Haema 2010; 1(1): 92-102
by S. Masouridis
Haematology Clinic, National and Kapodistrian University of Athens
Abstract
Mature T/NK-cell lymphomas are relatively rare in Western populations, representing 12-15% of all non-Hodgkin lymphomas. Disease rarity in combination with histologic heterogeneity hampered the research of the biology of PTCL for decades. Recently, the extensive use of immunophenotypic and molecular techniques increased the diagnostic accuracy of T/ΝΚ–cell lymphomas. Three rare, relatively newly recognized distinct clinico-pathogical entities will be reviewed here. Hepatosplenic T-cell lymphoma is characterized by hepatosplenomegaly without lymphadenopathy, clinically significant cytopenias and marked sinusoidal infiltation of spleen, liver and bone marrow by cytotoxic T-cells usually of γδ T-cell receptor type. Enteropathy-associated T-cell lymphoma arises in the gastrointestinal tract from the intraepithelial T lymphocytes and is highly associated with celiac disease. It is most commonly found in adults from geographic areas with a high incidence of celiac disease, such as Northern Europe. Extranodal NK/T-cell lymphoma, nasal type usually presents in the upper aero-digestive tract, especially the nasal cavity and it is characterized by extensive vascular destruction and tissue necrosis. A consistent association with Epstein-Barr virus has been observed. The disease has a unique geographic distribution, affecting mainly populations in Asia and Central/South America. These lymphoma subtypes show an aggressive clinical course and current treatment modalities appear to be ineffective in most patients. Development of novel agents and new strategies are required to improve survival but disease rarity does not allow the analysis of large series of patients.